Oral Administration Of Glycine Increases Extracellular Serotonin But Not Dopamine In The Prefrontal

[Ulvi]

Abstract
AIM: Glycine, one of the non-essential amino acids, has been reported to be effective in reducing negative symptoms of schizophrenia. Recently, we found that glycine improves subjective sleep quality in humans. The aim of this study was to investigate the effects of oral glycine administration on endogenous 5-hydroxytryptamine (5-HT) and dopamine in the prefrontal cortex (PFC) of living rats.

METHODS: Microdialysis probes were inserted stereotaxically into the rat prefrontal cortex. Cortical levels of 5-HT and dopamine were measured following oral administration of 1 or 2 g/kg glycine, 2 g/kg d-serine, or 2 g/kg L-serine.

RESULTS: Both glycine and d-serine significantly increased extracellular 5-HT levels for 10 min, whereas dopamine levels remained unchanged. L-serine, in contrast, had no significant effects on 5-HT levels.

CONCLUSIONS: It is possible that the increase in 5-HT in response to glycine and d-serine was mediated by N-methyl-D-aspartate receptors. The transient increase in 5-HT in the PFC might be associated with the alleviation of negative symptoms in patients with schizophrenia and the amelioration of sleep quality in patients with insomnia.

© 2011 The Authors. Psychiatry and Clinical Neurosciences © 2011 Japanese Society of Psychiatry and Neurology


So , glycine increases serotonin ? What do you think?

 

[Makrosky]

Interesting...

I react very bad to Glycine, every time I take it. Rebound anxiety, depression... I tried two brands. Not for me. Don't know if it's because of serotonin... I doubt it. But it's not a magic bullet, that is for sure.

 

[Mittir]

If Glycine was given without carbohydrate that can lower blood sugar
from increased insulin secretion. Insulin also causes tryptophan to
cross blood brain barrier.

 

[BastiFuntasty]

Well the dose is like 70-160g in humans....
Most positive studies are done in very very low doses.

 

[Tarmander]

I've always noticed glycine gives me some kind of viral infection. Seems to lower my immune system in some respect. I have an auto immune though so take that for what it's worth. Also helps me sleep and lowers blood sugar.

 

[Benjamin Button]

Yeah the dose is HUGE. Haidut gave a study recommendation of 1.5 g total for positive affects not "1 to 2 g per kg"

 

[What-a-Riot]

Yeah the dose is HUGE. Haidut gave a study recommendation of 1.5 g total for positive affects not "1 to 2 g per kg"

i think that rat dose only translates to like .75-1.5 grams in a human

 

[Giraffe]

i think that rat dose only translates to like .75-1.5 grams in a human

Do you mean 0.75-1.5 g/kg? Or total?

 

[What-a-Riot]

if I recall right you divide rat doses by about 10 to get the human equivalent, so total.

looks like that's like its actually 6 you divide by according to this though
http://www.fda.gov/downloads/drugs/guidances/ucm078932.pdf

 

[PakPik]

So , glycine increases serotonin ? What do you think?

Glycine is a coactivator of the NMDA receptor (the other activator is glutamate). That way it may be excitatory.
Some people react with excitotoxic-like symptoms to glycine, even with low amounts and after a well balanced meal -so it doesn't always have to do with sugar-. Could this account for an increase in serotonin?
However, glycine can also have GABA-like, inhibitory actions.
So, some people react to glycine in a excitatory/glutamate way, other people get the relaxing, GABA-like effects from it. It depends on the underlying brain chemistry.

I've always noticed glycine gives me some kind of viral infection. Seems to lower my immune system in some respect.

Glycine increases some of the immune-suppressive cytokines and lowers some of the antiviral, antibacterial aspects of immunity. Personally, when I do take glycine, I always make sure to take a very low dose to avoid the immunesuppression.

 

[Tarmander]

Glycine is a coactivator of the NMDA receptor (the other activator is glutamate). That way it may be excitatory.
Some people react with excitotoxic-like symptoms to glycine, even with low amounts and after a well balanced meal -so it doesn't always have to do with sugar-. Could this account for an increase in serotonin?
However, glycine can also have GABA-like, inhibitory actions.
So, some people react to glycine in a excitatory/glutamate way, other people get the relaxing, GABA-like effects from it. It depends on the underlying brain chemistry.


Glycine increases some of the immune-suppressive cytokines and lowers some of the antiviral, antibacterial aspects of immunity. Personally, when I do take glycine, I always make sure to take a very low dose to avoid the immunesuppression.

Yeah inflammation, estrogen, and the immune system seem to be bound together in ways that are a little hard to decipher. At what point of lowering inflammation and estrogen do you start getting bad immune-suppression is the question. For me it seems that these substances like glycine make me sick relatively quickly, although I always feel better while sick if that makes sense. I think the longest I went was about two weeks with a flu like cold/tiredness before I called it quits because it was affecting my work. That was with Cascara. Part of me wonders if I was able to just commit to that sickness, and just lay around sick with very low inflammation, whether I would pull out of it after a few months.

 

[PakPik]

Part of me wonders if I was able to just commit to that sickness, and just lay around sick with very low inflammation, whether I would pull out of it after a few months.

Low inflammation does not equal health. Inflammation is good to have when needed in the way needed (I am not talking about damaging, senseless irritation; I am talking about an immune system that is perfectly able to act when needed and to the extent needed). This is a complex subject, as you say, but I'm sure a lot of people would be surprised at how many of the so called inflammatory diseases are instead diseases where immune suppression rules. They would be surprised at how many of the antiinflammatory, immunesuppressive substances promote, directly or indirectly, irritation, fibrosis and tissue degeneration.

As far as I have seen, the subject of inflammation-immunity is a subject that is not well represented and is terribly misinterpreted.

People would be surprised to know that aspirin powerfully strengthens the inflammatory response when taken in low-to-moderate doses, while at the same time lowering irritation. Or better said, it basically nullifies immunesuppression from high Prostaglandin E2 and primes the immune system for a stronger pro-inflammatory response when called for.

Prostaglandin E2 is called an "inflammatory" mediator, but it usually acts as an immunesuppressant -except when in very tiny concentration-. It technically is an anti-inflammatory substance when you get beyond a tiny amount of it -which lots of people with chronic conditions have-.

The effects of estrogen on immunity are dose and context dependent. Estrogen can be either immunesuppressant or immune-enhancing depending on how much, where and how it acts. It can also be irritating while being immunesuppressant; one doesn't exclude the other. Like Ionizing radiation -which has estrogen like actions-: it is powerfully immunesuppressant while at the same time terribly irritating and tissue damaging.

 

[Tarmander]

Low inflammation does not equal health. Inflammation is good to have when needed in the way needed (I am not talking about damaging, senseless irritation; I am talking about an immune system that is perfectly able to act when needed and to the extent needed). This is a complex subject, as you say, but I'm sure a lot of people would be surprised at how many of the so called inflammatory diseases are instead diseases where immune suppression rules. They would be surprised at how many of the antiinflammatory, immunesuppressive substances promote, directly or indirectly, irritation, fibrosis and tissue degeneration.

As far as I have seen, the subject of inflammation-immunity is a subject that is not well represented and is terribly misinterpreted.

People would be surprised to know that aspirin powerfully strengthens the inflammatory response when taken in low-to-moderate doses, while at the same time lowering irritation. Or better said, it basically nullifies immunesuppression from high Prostaglandin E2 and primes the immune system for a stronger pro-inflammatory response when called for.

Prostaglandin E2 is called an "inflammatory" mediator, but it usually acts as an immunesuppressant -except when in very tiny concentration-. It technically is an anti-inflammatory substance when you get beyond a tiny amount of it -which lots of people with chronic conditions have-.

The effects of estrogen on immunity are dose and context dependent. Estrogen can be either immunesuppressant or immune-enhancing depending on how much, where and how it acts. It can also be irritating while being immunesuppressant; one doesn't exclude the other. Like Ionizing radiation -which has estrogen like actions-: it is powerfully immunesuppressant while at the same time terribly irritating and tissue damaging.

Well said. I think, at least around here, people know that a suppressed immune system can be apart of the auto immune soup just as much as an "over active" immune system. Definitely not super clear though where the lines lay.

 

[milk_lover]

Ok this explains why I get bloated from pure glycine powder even though I take them with sugar and not more than 4g per dose. I thought glycine was probably flushing estrogen from my system that's why I get bloated. Maybe it's increasing my serotonin?

 

[Mittir]

Ok this explains why I get bloated from pure glycine powder even though I take them with sugar and not more than 4g per dose. I thought glycine was probably flushing estrogen from my system that's why I get bloated. Maybe it's increasing my serotonin?

Another explanation is the allergen RP talks about in Isolated
amino acids. Even gelatin used in Lab experiment is shown to have endotoxin.

 

[milk_lover]

Another explanation is the allergen RP talks about in Isolated
amino acids. Even gelatin used in Lab experiment is shown to have endotoxin.

That makes sense. Glycine slotted in gelatin capsules is very convenient though, especially if I am at work and I eat steak. Maybe little cypro with it could eliminate its bad effects?

 

[Lokzo]

Excess of Glycine has been correlated with a number of degenerative diseases and excitotoxicity:

Glycine-induced CA1 excitotoxicity in the rat hippocampal slice

The electrophysiological pattern of glycine injury was similar to the excitotoxic damage produced by 8 min exposure to sodium glutamate 9 mM.

Glycine-induced CA1 excitotoxicity in the rat hippocampal slice. - PubMed - NCBI

Glycine-induced neurotoxicity in organotypic hippocampal slice cultures.

Glycine-induced neurotoxicity in organotypic hippocampal slice cultures. - PubMed - NCBI

Contribution of endogenous glycine site NMDA agonists to excitotoxic retinal damage in vivo.

These results suggest that the severity of excitotoxic retinal damage in vivo depends on the levels of both glycine and D-serine.

Contribution of endogenous glycine site NMDA agonists to excitotoxic retinal damage in vivo. - PubMed - NCBI

Progression of ischaemic stroke and excitotoxic aminoacids.

43 (33.6%) patients had progressing ischaemic stroke. Concentrations of glutamate and glycine in plasma and CSF were higher in patients with progressing stroke than in those with stable cerebral infarcts (p < 0.0001).

Progression of ischaemic stroke and excitotoxic aminoacids. - PubMed - NCBI

 

[LeeLemonoil]

Well that merits looking into. I naively thought glycine is a net positive in every way - mimicking methionine restriction and there are studies indicating strong mitochondria-generating and regenerating ability.

 

[LeeLemonoil]

Since taurine is such a similar substance, would the negative effects described here for glycine apply for it also?

 

[TreasureVibe]

Since taurine is such a similar substance, would the negative effects described here for glycine apply for it also?